As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#1 HF RADIO INTERMITTENT. AT TIMES COULD RECEIVE BUT NOT TRANSMIT. GROUNDED - YES. REMOVED AND REPLACED HF #1 TRANSCEIVER AND CAPT'S HANDMIC PER B737-900 AMM 23-11-21. INSTALLATION TEST OF HF #1 SYSTEM GOOD PER AMM 23-11-21-400-801. HF #1 SYSTEM TEST GOOD PER AMM 23-11-00-730-801.